The invention discloses a test system and a test method of an electric automobile high-voltage electric system. The test system comprises a master control PC (Personal Computer), a batter management system, a to-be-tested high-voltage electric system, a discharging cabinet, a charging cabinet, a constant-current source, a constant-voltage source, an environment simulation box, a rain simulation box, a salt mist simulation box and a test battery set, wherein the battery management system and the to-be-tested high-voltage electric system are controlled by the master control PC. The test method comprises conventional function test steps and reliability test steps. According to the test system and the test method, disclosed by the invention, a standard system and a test label are adopted for testing the electric automobile high-voltage electric system, the defect of the nonstandard test of an existing high-voltage electric system is removed, the quality test of the high-voltage electric system is evidence-based, the operability and the controllability of the high-voltage electric system are increased, the unification of the test method of the electric automobile high-voltage electric system and the test standard is promoted, a severe automobile working condition can be adapted by the high-voltage electric system, the quality of the high-voltage electric system is increased, the safety of a passenger is increased, and the development of a new-energy electric automobile industry is facilitated.